Telephone repeater system.



H. B. STONE.

TELEPHONE REPEATER SYSTEM. APPLICATION IILED 11111.15. 1909.

1,025,167; I Patented May 7. 1912.

-: ean er.

systems and its object is to simplify and ima prove the etficiency of such systems in the are quite closely balanced efficient operation ceiver element thereof and causes the appaproposed to divert from the receiving etcment a certain portion of the current dew orgy-developed by the transmitting element.

several elements or the repeater system in or equivalent external devices is rendered wound on a common. core, its primary s'rnrns ragnnr OFFICE.

HENRY B. STONE, OF PROVIDENCE, RHODE ISIirluhTD-v TELEPHONE REPEA'IER SYSTEM.-

Ap'plication filed January 15,

Specification of Letters Eatent.

ratenteaiua *7, i912. 1909. Serial No. 472,449.

To all whom it mag concern .Be it known that I, HENRY B. Sronn, a citizen of theUnited States, and a resident of Providence, in the county of Providence H y invention relates to telephone repeater manner hereinafter described.

In telephone repeater systems which are bridged across the main line it has been found-that unless the two sections'ot' the'line is impossible.

It has heretofore been proposedto connect the main circuit elements of a telephone re.- peater in series with the main line and so in as I am aware such series systems have proven. unsatisfactory because the energy imparted tothe line by the transmitter element of the repeater over-excites the reratus to sing In order to overcome this. defect certa n auxiliary apparatus in the nature of external artificial lines has been;

veloped by the transmitting element. he use of such external apparatus impairsthe eficiency of the system by wasting the en- In the present invention 1 associate the such manner that the use of artificial lines unnecessary and all the energy produced by the transmitting element of the repeater is efie'ctive for reinforcing the original main line current. I

In carrying out my invention I employ the usual repeater consisting essentially of a receiving circuit including a receiver and a transmitting circuit including a transmitter and a source of electrical energy, and I asso ciate said circuits with the main line by means of a main repeating coil constructed to weaken the currents developed by the transmitting circuit in the receiving cir cuit, so that there is no tendency to the continuous operation of the apparatus commonly known. as singing This -repeating coil preferably has four; windings order to counteract the weakening an adjustable core.

windings' being connected in series with the two sides of the line'circuit respectively and arranged to act cumulatively on the receiving circuit, and its secondaries being connected in series with the transmitting and receiving circuits respectively. In

currents developed in the receiving circuit by the transmitting circuit I may provide an auxiliary repeating coil inductively connecting said circuits and preferably having In the drawing which accompanies and of the forms a part of'this specification the figure represents in diagram one embodiment o my invention.

In'the figure, I, 1 represent the main line having terminal stations A B. The primary windings 2 2 of the main repeating coil are connected in series with the two sides orthe main line respectively. The secondary winding 5 of the repeatlng CO1l 1S connected in series with the transmitting circuit which includes the battery 6 or other suitable source of electrical energy and the trans mitter 7. The secondary winding 3 of said repeating coil is connected in series with the 7 receiver or receiving helix 4 and the latter is located so as to control the operation of the transmitter 7. The primary winding 8 of the auxiliary repeating coil is connected as shown in series with the transmitting circuit and the secondary winding 9 thereof is included in the receiving circuit.

C represents the common core for the windings of the repeating coil and D is the adjustable core of the auxiliary repeating coil. c The pulsations of current in the main line develop similar pulsations in the winding 3 of the receiving circuit which energizes the receiver tand cause very much stronger pulsations of current to flow vin the transmltting' circu t. The strong current pulsations 1n the transmitting circult develop in the winding 3 currents opposing those developed therein by the main line.

current so that there is no tendency for the mutual reaction whichordi-narily produces singing. in telephone repeaters. A' certain portion of the energy of the current flowing in the transmitting circuit is translated to the receiving. circuit by the 'aux iliary repeating coil 8, 9 andfopposes the current which is induced in the winding 3 bythat which flows in the-winding 5, the

current developed in the receiving circuit by said auxiliary repeating coil being in the same direction as that originally induced in said receiving circuit by the current flowing in the main. line. The result is that the current in the receiving circuit is maintained at its full strength or ata value depending upon the adjustment of the core D with respect to the windings 8,9.;

and isnot wasted by external devices suchas artificial lines heretofore used to tone down or counteract theover excitation of the receiver.

The primary currents, or those developed in the transmitting or primary circuit,- are represented by short solid arrows. The initial or repeating line currents are represented by long solid arrows. The reprosecondary circuit 1 l, passing through the winding 2 (or. through the windings 2 2, ifboth windings be used) develop similar pulsations in the winding 3 of the receiving or tertiary circuit which energize the receiver 4 and cause very much stronger pulsations of current from the battery 6 to flow in the transmitting or f primary circuit. These strong current pulsations spend their entire energy in developing similar ulsations in the main line only, such transation of energy to the main line being accomplished by the transformer whose primary consists ofthe winding 5 and whose secondary consists .of the winding '2 (or the windings 2 2'.) v v In order to prevent any portion of the energyof the current pulsations developed in the transmitting or primary circuit from being translated to the receiving or tertiary circuit and thereby operating the receiver at (said operation of said receiver producing singing or howling) the transformer 8 9 is provided, the primary 8 being in the transmitting or primary circuit and the secondary 9 being in the receiving or tertiary circuit.

Thestrong pulsations of the primary current which pass through the winding 5 to the left, as shown by the short solid arrow, would develop in the secondary 3- relatively strong currents flowing to the right as shown by the long broken arrow placed above said secondary, were it not for the transformer S 9.

The strong pulsations of'primary current which pass down the primary 8, as shown by the short solid arrow, would develop in the secondary 9 relatively strong currents flowing upward as shown by the long broken arrow placed to the right of said. secondary, were it not for the transformer 5 3.

hen, by means of the adjustable core I),

or other suitable means, the inductive effect of'the primary 8 on the secondary 9 is properly adjusted, the strong pulsations of primary current flowing in the primary 8 develop 1n the secondary. 9 an electrolnotlve force which is equal in value and opposite tcry current. In fact, the only currents that can possibly flow in said receiving or tertlary circuit are those which are developed therein by the lnductlve eiiect of the lnitial .or repeating line currents flowing in the winding 2 (or the windings 2 2) on the secondary 3, such currents being shown by the short broken arrows. Accordingly the two long broken arrows which are placed. above the secondary 3 and to the right of the secondary 9 do not really represent currents at all, but merely equal and opposite electromotive forces.

" After the best position for the core D has been ascertained experimentally, no further adjustments of the system are required for adapting the same to lines of varyil'ig electrical properties and by means of this system long lines may be connectedto short lines without the use of any balancing apparatus.

Itwill be readily apparent that the winding 5 may be eliminated and the terminals bv the of the transmitting system connected terminals of the winding 3.

Many other modifications will suggest themselves to those skilled in. the art without departing from the principle of my in vention, and accordingly I do not desire to be limited tothe particular system of-circuits herein described for the purpose of more fully disclosing my invention.

I claim: I

1. A telephone repeater system comprisingv a main line, a receiving circuit includ ing a receiver, and a transmitting circuit including a transmitter and a source of elcc trical energy; a main repeating coil having its primary windings connected injscries with the two sides of said main line, re spectively, and arranged to act cumulativclv on said receiving circuit, said repeating coil having its secondary windings connected in series wltn'saidtransinitting and receiving CllClllt-S, respect1vely; and an auxiliary repeatmg 0011 having its primary winding connected in series With said transmitting.

, ing a receiver, and a transmlttin circuit including a transmitter and a so rce of electricalenergy; a main repeating. coil having primary windings connected in series vely, and arranged to act cumulatively on said-- receiving circuit, 'said repeating coil having its secondary windings connected in series with said transmitting and receiving circuits respectively; andflan auxiliary repea'ting coil having its primary windings connected in serieswith said transmitting circuit and its secondary winding connected in series with its receiving circuit; the said main repeatiug'coil being so arranged that the current developed by "said transmitting circuit said receiving circuit is opposed .to the current developed therein. by the main line and said auxiliary repeating coil being so arranged that the current developed by 1 said auxiliary repeating coil in said receiving circuit is in the same direction as that developed therein by said-main line.

3. A telephonerepeater system compris ing a main line, a receiving circuitincluding a receiver, and a transmitting circuit including a transmitter and asource of electrical energy;- a main repeating coil having its primary windings connected in series vwith the two sides of said main line, respecsaid receiving circuit, said repeating coil having itssecondary windings connected in series with said transmitting and receiving circuits, respectively; hand an auxiliary repeating coil having its primary Winding connected'in series ,with said transmitting circuit and its seconda ty winding connected in'series with said receiving circuit; the said main repeating coii i being arranged to weaken the current developed by said trans mitting circuit in saidreceiving circuit. 4. A telephone repeater system c'o hprising a main line, a receiving circuit includincluding a transmitter and a source of electric al energy; a main/repeating coil having its primary windings connected in series iepeater system comprismg a main line, a' receiving c1rcuit includ 1th the two sides of said main line, respec-' J tively, and arranged to-act cumulatively on v ing a" receiver, and a transmitting circuit with the two sides of said' main line,

spectiv'ely, and arranged to act cumulatively on said receiving circuit, said repeating coil havi g its secondary windings connected in y series with said transmitting and receiving circuits,respectively; and an auxiliary r vpeatng COll having its primary windai connected in series'with said transmittingclrcult and Its secondary wlndlng connected mainv repeating coil being so arranged that the current developed by said transmitting circuit in said receiving circuit is opposed ice the current developed therein by the main 5. A telephone repeater system compris ing a main line provided with terminal stae tions, intermediate repeating apparatus in-. cluding a eceiving circuit and a transmit:

ting circuit: and having its main "circuit "elements connected in series with said stations,

and an auxiliary repeating coil inductively connecting said transmitting and receiving circuits, said auxiliary repeating coil being? arranged to strengthen the current developed by the main line in said receiving circuit,

6. A telephone repeatersystem compris ing a-main line, provided with terminal stations, intermediate repeating apparatus including a recelvlng circuitand a transmitting circuit and having its main circuit elements connected in serieswithsaid stat-ions, an auxiliary repeating coil inductively connecting said transmitting and receiving circuits, said auxiliary repeating coil being arranged to strengthen the current developed by the main line 'in said receiving circuit,

,anda core for said auxiliary repeating coil adjustable 'with' respect to the windings thereof.

7 .-A telephone repeater system comprising a main line provided with terminal stations, intermediate repeating apparatus including a receiving circuit and a transmitting circuit and having its main circuit elements connected in series with said stations, an auxiliaryrepeating coil inductively con-' necting said transmitting and receiving circuits, said auxiliary repeating coil being arranged to strengthen the current developed by the main line in said receiving circuit, and means for varying'the inductive effect in series with it's receiving circu1t; the said between the windings of said auxiliary re-.

peating coil.

In testimony whereof, I have hereunto subscribed my name this 13th day of Jan. 1909.

HENRY B. STONE,

Witnesses:

OLIVER KENDALL, Jn, 

